Week 1 Fetal Heart Monitoring Flashcards
What is the role and function of the fetal sympathetic NS?
- Stimulates the release of catecholamines in response to interruptions in oxygenation and blood pressure
- INcreases FHR and caused peripheral vasoconstriction in fetus
What is an acceleration?
An abrupt increase in FHR.
- onset to peak less than 30 seconds
- A peak of at least 15 bpm and must last 15 or more seconds.
- Cant exceed 2 minutes
What is the role and function of the fetal parasympathetic NS?
- Impulses orininate in fetal brain stem
- Impulses carried by the vagas nerve and heart
- when stimulated, reduces baseline
What is the MOST CRITICAL predictor of adequate fetal oxygenation during labor?
FHR variability
What is a variable deceleration?
Abrupt decrease in FHR.
- onset to lowerst point in less than 30 seconds
- -A dip of at least 15 bpm and must last 15 or more seconds.
- Cant exceed 2 minutes
Fetal arrhythmias Can appear as what on a FHR
Tachycardia, decrease in variability
Fetal congenital anomalies Can appear as what on a FHR
Minimal to absent variability, Decelerations
Pre-existing fetal neutologic abnormalities Can appear as what on a FHR
Minimal to absent variability, absence of accelerations
What is Minimal variability?
Amplitude range detectable but is less than or equal to 5
Late decelerations are often caused by ____
COmpression of vessels
Variable decelerations are often caused by ___
Umbilical cord compression
What is Tachysystole?
Excessive uterine activity. More than 5 contractions in a 10 minute period averaged over 30 minutes
-Can result from spontaneous or stimulated labor
How do BP changes effect FHR?
- Decreased FHR to decrease BP
- Increased FHR to resolve hypotension
Early decelerations are often caused by ____
Head compression
What is uterine activity?
Based on the number on contractions that occur in a 10 minute segment averaged over 30 minutes
What is absent variability?
Undetectable amplitude range
What are the interventions for VariableDecelerations
- Change position
- Turn off pitocin
- Increase Fluid rate
- Begin O2 by face mask
- Notify MD
- Check BP
- Possible C section needed
- A possible candidate for amino infusion
How is FHR effected by increased CO2/decreased oxygenation?
It increased in an effort to increase oxygenation or decrease CO2
What are the interventions for Late Decelerations
- Change position
- Turn off pitocin
- Increase Fluid rate
- Begin O2 by face mask
- Notify MD
- Check BP
- Possible C section needed
What is a prolonged deceleration?
An acceleration lasting more than 2 minutes but no longer than 10 minutes
Fetal autonomic response to changes in Intercranial and/or cerebral blood flow caused by transient compressions of the fetal head during uterine contractions Can appear as what on a FHR
Early decelerations
Fetal cardiac conduction abnormalities Can appear as what on a FHR
bradycardia
What causes changes in FHR baseline?
- Changes in fetal O2 and CO2 (chemoreceptors)
- Changes in fetal BP (baroreceptors)
What are recurrent Deceleration’s?
Occur withing 50% or more of contractions in any 20minute window
Transient disruption of 02 transfer from the environment to the fetus at the level of the umbilical cord Can appear as what on a FHR
Variable decelerations
Disruption of 02 transfer to the fetus resulting in transient hypoxemia during a uterine contraction Can appear as what on a FHR
Late decelerations
What is a prolonged acceleration?
An acceleration lasting more than 2 minutes but no longer than 10 minutes
What is moderate variability?
Amplitude range of 6-25
What is sinusoidal pattern?
a smmoth wave-like undulating pattern in FHR baseline with cycle frequency of 3-5 minutes that persists for 20 or more minutes
What is a late deceleration?
-Apparent symmetrical, gradual decreases and return of FHR associated with uterine contraction that occurs after the peak of a contraction
Fetal viral infections Can appear as what on a FHR
Bradycardia
What is an early deceleration?
-Apparent symmetrical, gradual decreases and return of FHR associated with uterine contraction.
What is the normal BPM range of FHR?
110-160
Transient disruption of 02 transfer from the environment to the fetus at one or more points in the O2 pathway Can appear as what on a FHR
Prolonged Decelerations
What is marked variability?
Amplitude range of 26+
What is normal uterine activity?
5 or less contractions in a 10 minute segment averaged over 30 minutes
What are intermittent Deceleration’s?
Occur with less than 50% of contractions
Fetal heart defects Can appear as what on a FHR
Brady cardia
